So here is an impolite question: How big is your belly? What size are your thighs? How much of your body is squishy? If you can't tell me how fat you are, you'll never get thin.

Fat will kill you. Very literally. Lugging around that excess body fat isn't just cumbersome, it can lead directly to heart disease, stroke, diabetes and some types of cancer. And the first step to getting rid of it is saddling up to the scale and addressing it. That's what we're going to do in this post. In a very public way.

I've got a couple of hundred invitations to Fitocracy to hand out (see the bottom of this post), and a few different ways to take part in exercises and challenges so we can do this thing together. But first, let's talk precommitment.

Burn The Ships

Starting a new fitness regimen is easy breezy. Following through is hard. Everyone is different, but two things always help me keep it up: precommitment, followed by tracking. We're going to use the Web and software to do both.

The popular legend of Cortes goes that when he landed in Vera Cruz, he burned his ships so his men couldn't retreat. It was go forward, or die. (Cortes was kind of a dick.) You're lucky; you don't have to light any fires. Except maybe under your ass. But a surefire method to force yourself to do something is by commiting in advance in a way that makes it hard to back out of. Precommiting.

One way of doing that is by making your goal public. It makes it harder for you to say, "screw it, I'm going to sleep in and then have a jelly donut" when you know everyone is watching you. And nothing is as public as the Internet. Set a goal, post it online, and you've publicly precommitted to doing something in a way that people can call you out on.

That's why I'm pledging to post my stats each week. (I'm also making my Withings scale data publicly available.) I'd love it if you can make a public commitment too. Say something in the comments, announce it on the Fitmodo forum, tell people on Facebook or Twitter. However you go about it, I'd like to urge you to set a goal, and publicly commit to getting yourself back in shape with the rest of us on Fitmodo.

I'm not asking you to measure your poo. But I would like you to start tracking stats, and to make them public. Measure the amount of time you work out each week, and publish it online. Post your weigh-ins. Talk to other people in the Forums, or in one of the activity-tracking groups we've set up. Let people know what you're up to in whatever way you're most comfortable with. We've got a few tools to help you do that (including invites to a hard-to-get-in fitness web app) and in the coming weeks we're going to explore a lot more. But for starters, here are a few metrics that are useful to know and track. Feel free to share these in the comments, which double as a de facto forum where you can sound off on a given week's topic.

Weight

You totally know this one! It's the measurement of the force of gravitational pull on your delightful bottom. And the rest of you too. It's easy to find. Step on a scale. Taking your weight on a daily basis is one of the best ways to lose weight. In other words, this number is going to go down. Yay!

Body Mass Index

Fancy scales will measure this for you, but you don't need them. Do you know how much you weigh? Do you know how tall you are? Then you know your BMI. Take your weight in pounds, multiply it by 703, and then divide it by your height in inches squared. You can also use a scale that will calculate this for you, like a Tanita or Withings. Or you can just plug your numbers into an online calculator.

Body Fat Percentage:

This one's trickier. You either need a fancy scale that sends electric current up through your body, calipers, or a gym that measures this for you. But it's okay! This is the least important metric. It's a nice bonus if you know it, but don't sweat it.

Resting Heart Rate:

As soon as you wake up, and before you get out of bed in the morning or even sit up, count your heart beats for one minute. (It might be helpful to keep a pad and pen by your bedside, if you don't use your smartphone as an alarm clock.) This is your resting heart rate (RHR). In the coming weeks, you're going to see it go down as well. Huzzah!

Maximum Heart Rate:

This won't change much if at all over the time you're working out. But it's useful to know, especially when combined with your resting heart rate, because later we're going to talk about training using heart rate zones. (And if you don't have a heart rate monitor; don't worry. You'll be able to swap in perceived effort.) Traditionally you find your max by either running until you almost puke (dangerous!) or by subtracting your age from 220 (inaccurate!). A better way is to take the Foster Threshold Test. It will give you a relatively accurate number without killing you. Here's how:

Exercise until your heart rate reaches 120 beats per minute. Continue for 90 seconds at that rate, and then say the Pledge of Allegiance. Can you say it comfortably? Increase your exertion level until your heart rate goes up by ten beats, and repeat. Continue until you can no longer say the pledge comfortably. If you're fit, divide that number by .8. If you're just getting into shape, divide it by .7. (More details here.)

Now that we've talked a little bit about the numbers to track, the question is how to track them. It can be as simple as a notebook, or spreadsheet, but I prefer automated software tools, especially ones that can log my cardio exercise for me. There are a host of programs that will do that for you, either by connecting to a fitness device or running as a smartphone app. Some of the more popular ones include TrainingPeaks, Garmin Connect, Runkeeper, Nike Plus, and Daily Mile. We're going to look at all those and more.

Fitmodo Challenges

Now it's time to combine precommitment with tracking. We're going to do that together in the Fitmodo groups and challenges. We've set up a couple of ways to get you started.

I wanted to start with something attainable, so I set a relatively modest goal: Run or walk five miles over the course of the week.

That's it! All of us can do this. We're going to ease our way into the bath together. Some of you will crank five miles out in a single run. For others, you're going to split it up, and hoof it out over the course of a week. Later on we're going to have a few different levels of challenges. But right now, let's just get everyone in the pool.

But what about a way for those of you who hate running to take part?

We've also got an Earndit challenge. Earndit awards points based on exercise across various formats. It gives you ten points per mile. So, over the next week, try to score 50 points for yourself. There's a competition to see who scores the most, and if that's you, I'll make sure to mention you next week. But I'm more interested in calling out those of us for whom even getting to 50 points represents a significant effort and lifestyle change. Because if you're just getting up off the couch, getting to 50 is harder than getting to 500 is for someone really sporty. But perhaps more interesting to you, earning points also lets you level up to win actual prizes worth actual money.

And then there's Fitocracy. Fitocracy turns exercise into a game, and tracks everything from swims to kettlebells. You earn points and level up based on how much you work out. The achievement you ultimately unlock will be a healthier you. I've set up a Fitocracy Gizmodo group you can join. Fitocracy is invitation-only, but it was kind enough to set us up with an invitation code that's good for a couple hundred of you to join. So if you're not already a member, you can join here, and it will automatically set you up in the Gizmodo group.

Vital Stats Week Two

Weight: 171 lbBMI: 25.3Fat Mass: 21 percentRHR: 64

And as promised, here are my vital stats, and workouts for the week. I went for three runs this past week, for a total of just under an hour and a half, and 7.14 miles. You can view them here on Runkeeper. It's not much, but it's a start.

Next week, we're going to dive into devices. Hope to see you back again.